The following generally relates to sub-floor assemblies and, more particularly, to a sub-flooring assembly which is to be placed under a sports floor.
As described in commonly assigned, U.S. Pat. No. 5,778,621, sports floors have certain requirements above and beyond floors used for non-athletic purposes. Athletic floors should have some degree of elasticity under load, and yet be quite firmly supported. Further, a sports floor should be uniformly supported and level throughout the entire surface so that there are no dead spots or uneven spots which could affect the activity occurring on the sports floor.
Numerous attempts have been made to design a sports floor with such ideal characteristics. Resiliency is typically obtained by implementing a shock absorbing system into the sub-floor. Shock absorbing systems are in wide use in sports flooring installations. Typical systems provide a sub-floor of softwood sleepers or plywood sheeting supported by isolated resilient pads. These designs allow deflection under active loads offering shock absorbency of the system to the athletic participant. Examples of shock absorbing systems are disclosed in U.S. Pat. Nos. 4,879,857 and 4,890,434. Referred to as floating systems, these sub-floors are not anchored to the concrete substrate but rather rest on individual resilient pad supports.
One way to improve stability of a sports flooring system is to anchor or fasten the sub-floor to the underlying concrete substrate. Anchored systems are especially resistant to buckling or upward movement associated with sports floors under changing environmental conditions. Furthermore, attempts have been made to combine the resiliency of floating systems and the stability of anchored systems. For example, U.S. Pat. No. 4,856,250 incorporates a suspended sleeper resting on resilient pads. The sleeper and pads are encased by flanges of a steel channel which are secured to a substrate by means of steel concrete anchors. U.S. Pat. No. 5,016,413 incorporates isolated sub-floor panels, typically two (2) plywood layers suspended on a resilient layer. U or T shaped steel channels are secured between the spaced sub-floor panels in a manner to allow outward flanges of the channel to rest upon a lower ridge in the plywood sub-floor. The channel is fastened to the substrate by means of concrete anchors.